Single lever self-locking cam handle



April 8, 1969 .1. M. SUDDARTH SINGLE LEVER SELF-LOCKING CAM HANDLE Sheet Filed Oct. 28, 1966 INVENTOR JACK M. 5000mm A] ram/5x3 April 8, 1969 J. M. SUDDARTH SINGLE LEVER SELF-LOCKING CAM HANDLE Filed Oct. 28, 1966 Sheet //vv/v ran JACK M; SUDOARTH AT OR/VEYS United States Patent Int. Cl. Gg 5/06 US. Cl. 74528 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a lens grinding and polishing machine and particularly to means for manually setting and maintaining the pressure between the lap and workpiece during the polishing operation. A pivotally mounted lever contacts a workpiece holder at one end and is connected at the other end to the self-locking cam handle by means of a coil spring and a second lever. The handle and said second lever are connected through a cam and locking assembly comprising a cylindrical collar secured to the handle having an elongated slot in its cylindrical surface. A roller or cylindrical pin is disposed in said slot. A cam member is rotatably disposed within the collarthe cam member being a part of said second lever. The entire assembly is surrounded by a cylindrical cap and operates in such a manner that when the handle is moved to a certain position, it will automatically maintain that position and thereby apply constant pressure through the second lever, spring and pivoted lever to the workpiece holder.

This invention pertains generally to improvements in lens grinding and polishing machines and, more particularly, relates to improvements in machines for polishing and fining the surfaces of cylindrical lens blanks. Machines of this type are comprised generally of a cylinder lap supported on a platform in which there is introduced an irregular movement referred to in the art as a breakup movement, together with means for maintaining the lens in engagement with the moving lap.

A principal objective of this invention is to provide means for manually setting and maintaining the pressure between the lap and workpiece during the polishing operation.

Another objective of the invention is to maintain a biased pressure on the lens blank from a spring.

A further objective of the invention is to maintain a baised pressure on the lens blank from a spring by using a single lever which when moved will maintain its pressure without any further action on the part of the operation.

These and other objects of the invention will become more apparent to those skilled in the art by reference to the following detailed description when viewed in light of the accompanying drawings, wherein like elements throughout the figures thereof are indicated by like numerals and wherein:

FIGURE 1 is a diagrammatic view of the invention;

FIGURE 2 is a detailed section view of the self-looking cam handle in a neutral position;

FIGURE 3 is a detailed section view of the self-locking cam handle in a locked position; and

FIGURE 4 is an exploded view of the self-locking cam handle.

Referring to the drawings, specifically to FIGURE 1, an abrading lap having irregular movements in a common plane is shown by the numeral 10. A lens blank or workpiece 12 to be ground or polished is attached by known means to a lens block 14. The lens block 14 is drivingly engaged by pins 16 which are carried by a spacer bar 18. The lens block 14, pins 16, and spacer bar 18 together comprise a work engager generally indicated by the numeral 19. A lever 20 having a depending leg 24 at one end and a ring 26 at the other end is pivoted about a fulcrum 22. The spacer bracket 18 is suspended from the leg 24 by conventional means while the ring 26 is connected to a coil spring 28. The coil spring extends vertically above the ring 26 of lever 20 and is connected by a ball and socket joint 29 to a lever arm 42. It can be seen that as the spring 28 is stretched from above, the lever 20 will pivot in a clockwise direction and increase the pressure between the lens blank 12 and the cap 10. The pressure thus imposed is a spring bias pressure which results directly from spring tensioning.

In order to allow an operator to select the proper spring tension a handle lock assembly 30 is provided. As best seen in FIGURE '4, the handle look assembly 30 comprises a cam 31, a pressure handle 34, a cylindrical roller guide 36, a roller or pin 38 and an outer roller housing 40.

The cam 31 is comprised of a cylinder 32 which has an arcuate flange 41 formed about the outer circumference at one end. One portion of the flange is extended to form the lever arm 42. Both the flange 41 and lever arm 42 are in a plane perpendicular to the longitudinal axis of the cylinder 32. A flat cam surface 44 is formed in the end portion of the cylinder 32 opposite the flange 41. A threaded aperture 46 is centrally located on the longitudinally axis of the cylinder 32.

The cylindrical roller guide 36 comprises a hollow cylinder adapted to slidably fit over the cylinder 32 of the cam 31. A slot 50 is located in the wall of the cylindrical roller guide 36 and is large enough to freely receive the cylindrical roller 38. The slot 50 commences at one end of roller guide 36 and extends for approximately one half of its length. As best seen in FIGURE 2, when the roller guide 36 is assembled over the cylinder 32 of the cam 31, the slot 50 is positioned opposite the cam surface 44. A chordal chamber 49 is thus formed between the interior of roller guide 36 and cam surface 44.

The pressure handle 34 has arcuate clamping arms 47 which conform to the outer surface of roller guide 36 and which are adapted to be clampingly engaged therewith by means of a clamping bolt 48. The clamping arms 47 are narrow enough to engage only that part of the outer surface through which the slot 50 does not extend.

The outer roller housing 40 is comprised of a hollow cap member 51 and a central bolt extension 52. The housing 40 is rigidly secured to the cam 31 by screwing the bolt 52 into the threaded aperture 46. The cap 51 is slidably received over the end portion of the roller guide 36 not occupied by the clamping arms 47 of the pressure handle 34. As best seen in FIGURE. 2, an interior wall 54 of the housing 40 forms a bearing surface for the roller 38. The handle 34 and the clamped roller guide 36 are pivotally supported on the cylinder 32 and the entire assembly as shown is pivotally supported on standards or cradles, shown on one side only in FIGURE 1, by means of stubs 53 also shown on one side only. It is to be understood that a stub and cradle arrangement is to be positioned on the other side of the entire assembly in supporting relationship.

In operation, counter-clockwise rotation of the handle 34 by the operator will cause both the handle and the clamped roller guide 36 to move as a unit from the position shown in FIGURE 2 to the position shown in FIG- URE 3. The movement of the roller guide 36 will push the roller 38 along the interior wall 54 of the outer roller housing 40. The lever arm 42 of the cam 31 will not be moved until the roller 38 makes contact with the end portion of the cam surface 44. The circumferential forces created by the handle 34 and transmitted through the roller guide 36 and roller 38, will then be transmitted to and cause rotation of the cam 32 and its lever arm 42, thus tensioning the spring 28. Such tensioning of the spring 28 will, in turn, operate the lens block engaging means 19 by pivoting the lever 20 clockwise about fulcrum 22, thus increasing the pressure between the abrading lap 10 and the lens blank 12. Once the handle 34 has been rotated the desired amount it is simply released. The desired amount is measured by the bias pressure which is perceptive measurement readily learned by an operator through experience. As shown in FIGURE 3, the handle 34 is selflocking in its released position. The downward forces exerted by the spring 28 on the lever arm 42 will be dissipated in compressing the roller rather than rotating it. \Vhen it is desired to decrease the lap-lens pressure, the handle 34 is rotated in the opposite direction, creating circumferential forces which readily move the roller 38. The cam 31 will not rotate until the roller engages the opposite end of cam surface 44.

The importance of the system can now be readily understood. The use of a tensioned spring to maintain a biased pressure between the abrading lap and the lens blank in combination with a self-locking handle means allows the operator to rotate a single lever, which when moved will maintain its pressure without any further action on the part of the operator.

What has been set forth above is intended primarily as exemplary to enable those skilled in the art in the practice of the invention and it should therefore be understood that, within the scope of the appended claims, the invention may be practiced in other ways than as specifically described.

What is new and therefore desired to be protected by Letter Patent of the United States:

1. In a lens polishing machine a linkage system comprising:

a work engaging member at one end of said linkage system,

a handle at the other end of said system pivotally supported for movement in first and second directions,

a lever connected at one end to said work engaging member and pivotally mounted intermediate its length,

a spring connected at a first end to the other end of said lever,

connecting means connecting said handle to the second end of said spring for spring-expansion against its natural bias when said handle is moved in said first direction,

said connecting means including locking means locking said handle against movement in said first or second directions from forces originating at said work ensaid locking means including a cylindrical collar secured to said handle and having an elongated slot in its cylindrical surface, a pin received in said slot, a cam member rotatably disposed within said collar, an arm connecting said cam to said spring, a cylindrical cap slidably disposed in close surounding relationship about said collar and pin and fixedly secured to said cam.

2. The improvement described in claim 1 wherein said cam is cylindrical with a flattened cam surface juxtaposed adjacent said pin to thereby form a chordal chamber with said collar, said pin having a diameter greater than the annular width of said collar whereby said pin extends into said chamber.

3. The improvement described in claim 2 wherein the width of said slot closely approximates the diameter of said pin whereby a movement of said handle and collar will wedge said pin between said flattened surface and the inner surface of said cylindrical journal portion whereby a further movement of said handle in the same direction will cause said arm to move against the bias of said spring.

References Cited UNITED STATES PATENTS 1,461,094 7/ 1923 Fellow 51-124 2,225,826 12/ 1940 Duifcns 51-124 2,715,803 8/1955 Bronson 51-124 HALL C. COB, Primary Examiner.

US. Cl. X.R. 51-124, 216 

